Blending of different types of crude oils is a common process in the oil industry. Such blending is done to achieve a number of goals, for example: (1) to reduce the size and number of downstream process equipment by improving the viscosity and/or density components of crude oil that must be processed; (2) to improve the pipeline transport capacity of a heavy and/or viscous crude by mixing with a lighter, less viscous crude oil so that the mixture has acceptable viscosity for pipeline transport; (3) to achieve certain pipeline quality specifications, for example a crude oil that exceeds the pipeline specification on elemental sulfur, total acid number (TAN) acid content can be mixed with crude that is low in these components so that the mixture is kept below the pipeline requirements; and/or (4) to achieve certain refinery quality specifications, a low quality crude oil that is not acceptable can be mixed with a high quality one such that the mixture fulfills such requirements and can be processed in the refinery.
Current systems for crude oil blending use either inline static mixers or dynamic mixers for crude oil mixing. In general, the primary difference between static mixers and dynamic mixers is that dynamic mixers require an external power source to drive the mixing.
Static mixers, such as the one depicted in FIG. 1, typically include one or more mixing elements placed in the pipe downstream of the point at which the crude oils are merged together into a single piping stream. Such mixers generally operate on the basis of hydrodynamics where the mixing action is caused by energy created from pressure lost. For low viscosity fluids, such mixers may be acceptable as the pressure loss over the mixer will be low or moderate, but where one or both of the oils have high viscosity, the pressure loss over the mixer can be unacceptably large.